Inhibition of prostate cancer cell growth in vivo with short hairpin RNA targeting SATB1

Abstract

Despite previous advances, the treatment options for prostate cancer remain limited. For the purposes of gene knockdown, the utility of RNA interference has been demonstrated and is considered to have therapeutic potential. In the present study, a short hairpin RNA (shRNA) was used to assess the effect of special AT-rich sequence binding protein (SATB1) downregulation on the growth and metastatic potential of prostate cancer in xenograft nude mice. A plasmid carrying shRNA targeting SATB1, pSilencer-SATB1-shRNA, was successfully engineered. Using this plasmid, significant downregulation of SATB1 mRNA and protein expression in the DU145 prostate cancer cells was observed. pSilencer-SATB1-shRNA was demonstrated to be markedly efficacious against prostate cancer xenografts in nude mice. These results may lead to a novel method of improving gene therapy efficacy against prostate cancer via regulating the function of SATB1.

Keywords: apoptosis; prostate cancer; short hairpin RNA; special AT-rich sequence binding protein 1.

Figure 1.

Immunohistochemical staining for SATB1 protein expression. (A) SATB1 protein is primarily located in the cytoplasm and cell membrane, dyed brown (magnification, ×400). (B) Comparison of the IOD values in each treatment group. The pSilencer-SATB1-shRNA vs. pSilencer, or PBS-treated groups (*P<0.05, n=6). SATB1, special AT-rich sequence binding protein 1; IOD, integrated optical density; sh, short hairpin; pSilencer, plasmid silencer.

Figure 2.

Western blot analysis of STAT1 protein expression. (A) Lane 1, PBC, lane 2 pSilencer; lane 3, pSilencer-SATB1-shRNA (B) Semi-quantification of western blot analysis demonstrating the level of SATB1 expression vs. the β-actin control. *P<0.05 vs. pSilencer and PBS-treated groups, n=6. SATB1, special AT-rich sequence binding protein 1; sh, short hairpin; pSilencer, plasmid silencer.

Figure 3.

Hematoxylin and eosin staining of tumor tissue samples. SATB1, special AT-rich sequence binding protein 1; sh, short hairpin; pSilencer, plasmid silencer.

Figure 4.

(A) Apoptosis staining using the TUNEL method in tumor tissue samples from each group. (B) Apoptosis rates based on TUNEL results. The pSilencer-SATB1-shRNA vs. pSilencer, or PBS-treated groups (*P<0.05, n=6). SATB1, special AT-rich sequence binding protein 1; sh, short hairpin; pSilencer, plasmid silencer.